Bimetallic materials for oilfield applications

ABSTRACT

Corrosion resistant and/or lightweight bimetallic cylinders used in tools and electric cables, including core surrounded by corrosion resistant alloy outer cladding materials, where the alloy clad may include such alloys as beryllium-copper based alloys, nickel-chromium based alloys, superaustenitic stainless steel alloys, nickel-cobalt based alloys, nickel-molybdenum-chromium based alloys, and the like. The core may be a low density core based substantially upon titanium or titanium alloys.

RELATED APPLICATION DATA

This patent application is a Continuation-In-Part of and also claims the benefit of U.S. patent application Ser. No. 11/330,957, filed Jan. 11, 2006.

BACKGROUND OF THE INVENTION

This invention relates to equipment used in wellbores, and methods of manufacturing and using such equipment. In one aspect, the invention relates to wellbore tools and electric cables constructed in part from corrosion resistant and/or lightweight bimetallic cylinders.

Generally, geologic formations within the earth that contain oil and/or petroleum gas have properties that may be linked with the ability of the formations to contain such products. For example, formations that contain oil or petroleum gas have higher electrical resistivity than those that contain water. Formations generally comprising sandstone or limestone may contain oil or petroleum gas. Formations generally comprising shale, which may also encapsulate oil-bearing formations, may have porosities much greater than that of sandstone or limestone, but, because the grain size of shale is very small, it may be very difficult to remove the oil or gas trapped therein. Accordingly, it may be desirable to measure various characteristics of the geologic formations adjacent to a well before completion to help in determining the location of an oil- and/or petroleum gas-bearing formation as well as the amount of oil and/or petroleum gas trapped within the formation. The zones to be analyzed can be vertically underneath the well bore surface opening or at angles deviated up to 90 degrees or more from the main well bore.

Logging tools, which are generally long, pipe-shaped devices, may be lowered into the well to measure such characteristics at different depths along the well. These logging tools may include gamma-ray emitters/receivers, caliper devices, resistivity-measuring devices, neutron emitters/receivers, and the like, which are used to sense characteristics of the formations adjacent the well. A wireline cable connects the logging tool with one or more electrical power sources and data analysis equipment at the earth's surface, as well as providing structural support to the logging tools as they are lowered and raised through the well. Generally, the wireline cable is spooled out of a truck or an offshore platform unit, over a pulley, and down into the well.

Wireline cables are typically formed from a combination of metallic conductors, insulative materials, filler materials, jackets, and metallic armor wires. Armor wires typically perform many functions in wireline cables, including protecting the electrical core from the mechanical abuse seen in typical downhole environment, and providing mechanical strength to the cable to carry the load of the tool string and the cable itself. Armor wire performance may also be dependent on corrosion protection. Harmful fluids in the downhole environment may cause armor wire corrosion, and once the armor wire begins to corrode, strength and pliability may be quickly compromised. Although the cable core may still remain functional, it is not economically feasible to replace the armor wire(s), and the entire cable must typically be discarded. Tools used in wellbore operations are also vulnerable to excessive corrosion in sour environments.

Conventionally, wellbore electrical cables utilize galvanized steel armor wires (typically plain carbon steels in the range AISI 1065 and 1085), known in the art as Galvanized Improved Plow Steel (GIPS) armor wires, which do provide high strength. Such armor wires are typically constructed of cold-drawn pearlitic steel coated with zinc for moderate corrosion protection. The GIPS armor wires are protected by a zinc hot-dip or electrolytic coating that acts as a sacrificial layer when the wires are exposed to moderate environments.

Commonly, sour well cables constructed completely of corrosion resistant alloys are used in sour well downhole conditions. While such alloys are well suited for forming armor wires used in cables for such wells, it is commonly known that the strength of such alloys may be limited. In the case of tools, to prevent corrosion, expensive alloys are commonly used. These alloys include but not limited to the families encompassing super austenitic stainless steels, cobalt based alloys, stainless steels, Ni-alloys etc. These alloys are extremely expensive and the cost involved in some cases does not permit their use in the certain oilfield environments.

As deviations in the well bores are increasing, the zones to be reached for evaluation or production may be at large angles relative to the well bore opening. To reach these zones, the cable and tools must be tractored, but the reach may be limited as cables and tools may not be sufficiently light. Furthermore, deviated well bores are typically sour as higher concentrations of corrosive agents are typically present.

Thus, a need exists for equipment used in wellbores which may be lower in weight and/or have improved corrosion resistance. Materials which may be useful to form wellbore tools and cables that can overcome one or more of the problems detailed above would be highly desirable, and the need is met at least in part by the following invention.

SUMMARY OF THE INVENTION

The invention relates to corrosion resistant and/or lightweight bimetallic cylinders, such as solid billets or tubes, useful in equipment for seismic or wellbore operations. The cylinders are composed of a corrosion resistant alloy-clad material with an optional low density core. The clad is designed to be resistant to corrosion as well as possibly resistant to galling and/or abrasion. When used, a low density core provides a lighter weight cylinder. The cylinder may be a solid body or a hollowed body. Cladding the cylinder core may be achieved by forming or extrusion techniques, for example. Also, the cylinder may be drawn or machined to a desired diameter.

Any suitable material may be used as the core. Examples of some suitable materials useful as the core material include, but are not necessarily limited to, steel, titanium (α-phase, β-phase, α/β-phase), titanium alloys, low alloy steels (e.g. 4000 series), stainless steels (e.g. 400 series, 300 series, 17-4PH, etc.), and the like. Any appropriate metal or alloy may be used for the corrosion resistant clad including, but are not necessarily limited to beryllium-copper based alloys, nickel-chromium based alloys, superaustenitic stainless steel alloys, nickel-cobalt based alloys, copper-nickel-tin based alloys, or even nickel-molybdenum-chromium based alloys. The corrosion resistant clad may also be an alloy comprising nickel in an amount from about 10% to about 60% by weight of total alloy weight, chromium in an amount from about 15% to about 30% by weight of total alloy weight, molybdenum in an amount from about 2% to about 20% by weight of total alloy weight, cobalt in an amount up to about 50% by weight of total alloy weight, as well as relatively minor amounts of other elements such as carbon, nitrogen, titanium, vanadium, or even iron.

The cylinders of the invention are useful as components in oil and gas exploration and production related equipment such as WHE-pressure control equipment, chains, marine terminations, tool housings, tractor housings, risers, casing tubings, pipes, coil tubings, springs, fasteners and couplers, centralizers, surface production facilities, wellhead equipment, dowhhole completion hardware, control lines, BHA assemblies, and the like.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention may be understood by reference to the following description taken in conjunction with the accompanying drawings:

FIG. 1 is a cross-sectional view of a typical prior art cable design.

FIG. 2 is a stylized cross-sectional representation of an armor wire design useful in some cables of the invention.

FIG. 3 is a cross-sectional representation of a general cable design according to the invention using two layers of armor wires

FIG. 4 is a cross-sectional representation of a heptacable design according to the invention, including two layers of armor wires.

FIG. 5 represents, by stylized cross-section, a monocable design according to the invention.

FIG. 6 illustrates a method of preparing armor wires useful in cables according to the invention.

FIG. 7 illustrates another method of preparing some armor wires useful in cables according to the invention.

FIG. 8 illustrates yet another method of preparing some armor wires.

FIG. 9 is a cross-sectional representation of cables of the invention which include a polymeric material disposed upon the armor wires.

FIGS. 10A and 10B illustrate one corrosion resistant cylinder embodiment of the invention in both. FIG. 10A is an isometric three dimensional rendering. FIG. 10B is a cross-sectional illustration.

FIGS. 11A and 11B represent a corrosion resistant hollow body cylinder embodiment of the invention.

FIG. 12 is an isometric three dimensional rendering of a cylinder according to invention which is a tubular with an O-ring groove.

DETAILED DESCRIPTION

Illustrative embodiments of the invention are described below. In the interest of clarity, not all features of an actual implementation are described in this specification. It will of course be appreciated that in the development of any such actual embodiment, numerous implementation- specific decisions must be made to achieve the developer's specific goals, such as compliance with system related and business related constraints, which will vary from one implementation to another. Moreover, it will be appreciated that such a development effort might be complex and time consuming but would nevertheless be a routine undertaking for those of ordinary skill in the art having the benefit of this disclosure.

This invention relates to equipment used in wellbores, and methods of manufacturing and using such equipment. In particular, the invention relates to wellbore tools and electric cables constructed in part from corrosion resistant and/or lightweight bimetallic cylinders, such as solid billets or tubes, for example, as well as methods of using the equipment in seismic and wellbore operations. Designs for oilfield equipment must often strike a balance between weight, strength, corrosion resistance and materials and manufacturing resources. In the case of wireline cables, the cables must support their own weights plus the weights of downhole tool strings. Tools should be designed and constructed in such way to maximize reach and resistance to corrosive material, while remaining reliable and functional. The use of a corrosion resistant alloy outer cladding material with an optional low density core addresses these needs. The outer clad is designed to be resistant to corrosion, abrasion, and galling. When used, the low density core provides a lighter weight material thus extending the potential reach of the tool string, for example.

While this invention and its claims are not bound by any particular mechanism of operation or theory, it has been discovered that using certain alloys to form an alloy outer clad upon a core to provide a bimetallic cylinder, provides components useful for forming wellbore cables and tools with resistance to corrosion, which possess reasonably high strength properties. Preferably, no greater than one corrosion resistant alloy outer clad is formed upon the core. In addition to corrosion resistance, the outer clad may also provide resistance to galling and/or abrasion. When the outer clad is formed on a low density core, lighter weight cables and tools may be produced. By low density core it is meant the core is form substantially from a material with a density up to about 4.8 g/cm³, for example, from about 4.2 g/cm³ to about 4.8 g/cm³. In the case of titanium and its alloys when used as a core, as it has a lower density material than steel, the resulting weights are significantly less.

The term “cylinder” as use herein means a cylindrical body which is solid, or a cylindrical hollowed body. When the cylinder is a hollowed body, such as a tube, the outer and inner surfaces both may have a corrosion resistant outer clad upon the core. The core used to form the cylinder may be a tube or a solid billet. The corrosion resistant material is clad onto the core, either upon the outer periphery of the core, the inner surface in the case of hollowed body cores, or both. Cladding the cylinder core may be achieved by forming or extrusion techniques, for example. The surface roughness of the core and/or the clad material can be controlled for bonding strength purposes. If a corrosion resistant clad is not required in the inside of a tube, then a solid bimetallic billet can be co-extruded and barrel drilled to obtain a tube, which may be acceptable in cases of short lengths.

Examples of suitable materials useful as the core material include, but are not necessarily limited to, steel (i.e. hypoeutectoid, eutectoid, hypereutectoid), titanium (α-phase, β-phase, α/β-phase), titanium alloys, low alloy steels (e.g. 4000 series), stainless steels (e.g. 400 series, 300 series, 17-4PH, etc.), and the like. Titanium has up to about 45% lower density than that of steel, stainless steels, super-austenitic stainless steels, cobalt based alloys, and the like. As described above, titanium can enable lower weight oilfield equipment. Some advantages of having lower weight are lower size transportation equipment, or the possibility to carry an increased number of similar equipment. The lighter weight may also allow simplified installation operations and improved safety.

While there are advantages as a lightweight material, titanium or titanium alloys, when used alone, is known to be somewhat unsuitable for oilfield equipment applications, particularly as titanium is subject to galling (damage caused by adhesive friction) when titanium parts rub against each other. As such, galling renders titanium difficult for an application such as cable armor wires or the outer surface of tools, where the tools and/or cable may be in contact with each other under high tensions. Galling resistance for titanium in cables can be mitigated by expensive alloying also and by creating an impurity layer on the surface of the wire. The impurities that can be created on the wire surface cannot be exposed to excessive torsional loading that the wire and the cable is exposed to during manufacturing and deployment, and the impurities can lead to potential fracture initiation sites. However, inventors have discovered that placing a outer cladding over a lightweight titanium or titanium alloy core can overcome the problems described above, or at least in part. The clad material also offers a significant increase in the corrosion resistance. This is typically useful when the equipment is used in highly corrosive environments such as sour and highly deviated wellbores.

While any suitable alloy may be used as a corrosion resistant alloy outer clad to form cylinders of the invention, some examples include, but are not necessarily limited to: beryllium-copper based alloys; nickel-chromium based alloys (such as Inconel® available from Reade Advanced Materials, Providence, R.I. USA 02915-0039); superaustenitic stainless steel alloys (such as 20Mo6® of Carpenter Technology Corp., Wyomissing, Pa. 19610-1339 U.S.A., INCOLOY® alloy 27-7MO and INCOLOY® alloy 25-6MO from Special Metals Corporation of New Hartford, N.Y., U.S.A., or Sandvik 13RM19 from Sandvik Materials Technology of Clarks Summit, Pa. 18411, U.S.A.); nickel-cobalt based alloys (such as MP35N from Alloy Wire International, Warwick, R.I., 02886 U.S.A.); copper-nickel-tin based alloys (such as ToughMet® available from Brush Wellman, Fairfield, N.J., USA); or, nickel-molybdenum-chromium based alloys (such as HASTELLOY® C276 from Alloy Wire International). The corrosion resistant alloy outer clad may also be an alloy comprising nickel in an amount from about 10% to about 60% by weight of total alloy weight, chromium in an amount from about 15% to about 30% by weight of total alloy weight, molybdenum in an amount from about 2% to about 20% by weight of total alloy weight, cobalt in an amount up to about 50% by weight of total alloy weight, as well as relatively minor amounts of other elements such as carbon, nitrogen, titanium, vanadium, or even iron. The preferred alloys are nickel-chromium based alloys, and nickel-cobalt based alloys.

The bimetallic cylinders of the invention are useful as components in oil and gas exploration and production related equipment including, but not necessarily limited to, armor wire for cables, or tools/equipment such as WHE-pressure control equipment (i.e. BOPs etc.), chains, marine terminations, tool housings, tractor housings, lubricators/risers, casing tubings, pipes (i.e. drill pipes etc.), coil tubings, springs, fasteners and couplers, centralizers for tractors and oil field tools, surface production facilities, wellhead equipment, dowhhole completion hardware, control lines, BHA assemblies, and the like.

In some embodiments of the invention, lightweight armor wires are used in cables, where the armor wires are prepared from a metal billet made of low density titanium or its alloy core and a outer clad made of a corrosion resistant metal, such as austenitic stainless steel, Inconel®, and the like. The clad may be extruded over the titanium core or may be formed over the core and then seam-welded. The billet is drawn to a smaller diameter to form armor wire stock. The ratio of clad thickness to core width or diameter remains constant as the billet is drawn to a smaller diameter. The completed armor wire density or weight per length can be as much as about 40% less than standard GIPS armor wire, with significant gains in strength to weight ratios.

Cables using armor wires of the invention generally include at least one insulated conductor, and at least one layer of high strength corrosion resistant armor wires surrounding the insulated conductor(s). Insulated conductors useful in the embodiments of the invention include metallic conductors, or even one or more optical fibers. Such conductors or optical fibers may be encased in an insulated jacket. Any suitable metallic conductors may be used. Examples of metallic conductors include, but are not necessarily limited to, copper, nickel coated copper, or aluminum. Preferred metallic conductors are nickel coated copper conductors. While any suitable number of metallic conductors may be used in forming the insulated conductor, preferably from 1 to about 60 metallic conductors are used, more preferably 7, 19, or 37 metallic conductors. Components, such as conductors, armor wires, filler, optical fibers, and the like, used in cables according to the invention may be positioned at zero helix angle or any suitable helix angle relative to the center axis of the cable. Generally, a central insulated conductor is positioned at zero helix angle, while those components a surrounding the central insulated conductor are helically positioned around the central insulated conductor at desired helix angles. A pair of layered armor wire layers may be contra-helically wound, or positioned at opposite helix angles.

Insulating materials useful to form the insulation for the conductors and insulated jackets may be any suitable insulating materials known in the art. Non-limiting examples of insulating materials include polyolefins, polytetrafluoroethylene-perfluoromethylvinylether polymer (MFA), perfluoro-alkoxyalkane polymer (PFA), polytetrafluoroethylene polymers (PTFE), ethylene-tetrafluoroethylene polymers (ETFE), ethylene-propylene copolymers (EPC), poly(4-methyl-1-pentene) (TPX® available from Mitsui Chemicals, Inc.), other fluoropolymers, polyaryletherether ketone polymers (PEEK), polyphenylene sulfide polymers (PPS), modified polyphenylene sulfide polymers, polyether ketone polymers (PEK), maleic anhydride modified polymers, perfluoroalkoxy polymers, fluorinated ethylene propylene polymers, polytetrafluoroethylene-perfluoromethylvinylether polymers, polyamide polymers, polyurethane, thermoplastic polyurethane, ethylene chloro-trifluoroethylene polymers (such as Halar®), chlorinated ethylene propylene polymers, Parmax® SRP polymers (self-reinforcing polymers manufactured by Mississippi Polymer Technologies, Inc. based on a substituted poly (1,4-phenylene) structure where each phenylene ring has a substituent R group derived from a wide variety of organic groups), or the like, and any mixtures thereof.

The insulated conductors may be stacked dielectric insulated conductors, with electric field suppressing characteristics, such as those described in U.S. Pat. No. 6,600,108 (Mydur, et al.), incorporated herein by reference. Such stacked dielectric insulated conductors generally include a first insulating jacket layer disposed around the metallic conductors wherein the first insulating jacket layer has a first relative permittivity, and, a second insulating jacket layer disposed around the first insulating jacket layer and having a second relative permittivity that is less than the first relative permittivity. The first relative permittivity is within a range of about 2.5 to about 10.0, and the second relative permittivity is within a range of about 1.8 to about 5.0.

Electrical cables using armor wires of the invention may be of any practical design. The cables may be wellbore cables, including monocables, coaxial cables, quadcables, heptacables, seismic cables, slickline cables, multi-line cables, and the like. In coaxial cable designs of the invention, a plurality of metallic conductors surrounds the insulated conductor, and is positioned about the same axis as the insulated conductor. In addition, for any cables of the invention, the insulated conductors may be further encased in a tape. All materials, including the tape disposed around the insulated conductors, may be selected so that they will bond chemically and/or mechanically with each other. Armor wires used in the invention make possible lightweight, lower modulus wireline cables, especially desirable for downhole tractor applications. Cables of the invention may have an outer diameter from about 0.5 mm to about 400 mm, preferably, a diameter from about 1 mm to about 100 mm, more preferably from about 2 mm to about 15 mm.

Armor wires may have titanium or its alloys placed at the core of the armor wires, as described hereinabove. An alloy with resistance to corrosion and reduction of galling is then clad over the core. The corrosion resistant alloy layer may be outer clad over the low-density core by extrusion or by forming over the core. The corrosion and improved galling resistant outer clad may be from about 50 microns to about 600 microns in thickness. The material used for the corrosion and improved galling resistant outer clad may be any suitable alloy that provides sufficient corrosion resistance and abrasion resistance when used as a clad. The alloys used to form the clad may also have tribological properties adequate to improve the abrasion resistance and lubricating of interacting surfaces in relative motion, or improved corrosion resistant properties that minimize gradual wearing by chemical action, or even both properties.

Cables include at least one layer of armor wires surrounding the insulated conductor. The armor wires comprising a low density core and a corrosion resistant alloy outer clad may be used alone, or may be combined with other types of armor wires, such as galvanized improved plow steel wires, superaustenitic stainless steel armor wires, or even wire rope armor wires, to form the armor wire layers. Preferably, two layers of armor wires are used to form preferred electrical cables of the invention.

Referring now to FIG. 1, a cross-sectional view of a typical heptacable design. FIG. 1 depicts a cross-section of a typical armored cable design used for downhole applications. The cable 100 includes a central conductor bundle 102 having multiple conductors and an outer polymeric insulating material. The cable 100 further includes a plurality of outer conductor bundles 104, each having several metallic conductors 106 (only one indicated), and a polymeric insulating material 108 surrounding the outer metallic conductors 106. Preferably, the metallic conductor 106 may be a copper conductor. The central conductor bundle 102 of typical prior art cables, although need not be, is typically the same design as the outer conductor bundles 104. An optional tape and/or tape jacket 110 made of a material that may be either electrically conductive or electrically non-conductive and that is capable of withstanding high temperatures encircles the outer conductor bundles 104. The volume within the tape and/or tape jacket 110 not taken by the central conductor bundle 102 and the outer conductors 104 is filled with a filler 112, which may be made of either an electrically conductive or an electrically non-conductive material. A first armor layer 114 and a second armor layer 116, generally made of a high tensile strength galvanized improved plow steel (GIPS) armor wires, surround and protect the tape and/or tape jacket 110, the filler 112, the outer conductor bundles 104, and the central conductor bundle 102.

FIG. 2 is a stylized cross-sectional representation of a lightweight cylindrical armor wire design. The armor wire 200 includes a low density core 202, surrounded by a corrosion resistant alloy outer clad 204. An optional bonding layer 206 may be placed between the core 202 and alloy outer clad 204. The core 202 may be generally made of any low density material such as, by non-limiting example, titanium and its alloys. Examples of suitable alloys which may be used as core strength members include, but are not necessarily limited to CP Grades 1, 2, 3, etc., Beta-C, Ti-6Al-4V. The core strength member 202 can include a titanium core for low density, or even plated or coated wires. When used, the bonding layer 206 may be any material useful in promoting a strong bond between the high strength core 202 and corrosion resistant alloy outer clad 204. The microstructure phase of the low density core can be alpha, alpha-beta or beta.

Referring now to FIG. 3, a cross-sectional representation of a general cable design according to the invention that incorporates two layers of armor wires. The cable 300 includes at least one insulated conductor 302 and two layers of armor wires, 304 and 306. The insulated conductor 302 may be a heptacable, quadcable, monocable, or even coaxial cable design. The armor wire layers, 304 and 306, surrounding the insulated conductor(s) 302 include armor wires, such as armor wire 200 in FIG. 2, comprising a low density core and a corrosion resistant alloy outer clad. Optionally, in the interstitial spaces 308, formed between armor wires, as well as formed between armor wires and insulated conductor(s) 302, a polymeric material may be disposed.

Polymeric materials disposed in the interstitial spaces 308 may be any suitable material. Some useful polymeric materials include, by nonlimiting example, polyolefins (such as EPC or polypropylene), other polyolefins, polyaryletherether ketone (PEEK), polyaryl ether ketone (PEK), polyphenylene sulfide (PPS), modified polyphenylene sulfide, polymers of ethylene-tetrafluoroethylene (ETFE), polymers of poly(1,4-phenylene), polytetrafluoroethylene (PTFE), perfluoroalkoxy (PFA) polymers, fluorinated ethylene propylene (FEP) polymers, polytetrafluoroethylene-perfluoromethylvinylether (MFA) polymers, Parmax®, and any mixtures thereof. Preferred polymeric materials are ethylene-tetrafluoroethylene polymers, perfluoroalkoxy polymers, fluorinated ethylene propylene polymers, and polytetrafluoroethylene-perfluoromethylvinylether polymers. The polymeric materials may be disposed contiguously from the insulated conductor to the outermost layer of armor wires, or may even extend beyond the outer periphery thus forming a polymeric jacket that completely encases the armor wires. The polymeric material may or may not be fiber reinforced.

A protective polymeric coating may be applied to strands of armor wire for additional protection, or even to promote bonding between the armor wires and any polymeric material disposed in the interstitial spaces. As used herein, the term bonding is meant to include chemical bonding, mechanical bonding, or any combination thereof. Examples of coating materials which may be used include, but are not necessarily limited to, fluoropolymers, fluorinated ethylene propylene (FEP) polymers, ethylene-tetrafluoroethylene polymers (Tefzel®), perfluoro-alkoxyalkane polymer (PFA), polytetrafluoroethylene polymer (PTFE), polytetrafluoroethylene-perfluoromethylvinylether polymer (MFA), polyaryletherether ketone polymer (PEEK), or polyether ketone polymer (PEK) with fluoropolymer combination, polyphenylene sulfide polymer (PPS), PPS and PTFE combination, latex or rubber coatings, and the like. Each armor wire may also be plated with materials for corrosion protection or even to promote bonding between the armor wires and polymeric material. Nonlimiting examples of suitable plating materials include copper alloys, and the like. Plated armor wires may even be cords such as tire cords. While any effective thickness of plating or coating material may be used, a thickness from about 10 microns to about 100 microns is preferred.

FIG. 4 is a cross-sectional representation of a heptacable design including two layers of armor wires. The cable 400 includes two layers of armor wires, 402 and 404, surrounding a tape and/or tape jacket 406. The armor wire layers, 402 and 404, include armor wires, such as armor wire 200 in FIG. 2, comprising a low density core and a corrosion resistant alloy outer clad. The interstitial space within the tape and/or jacket 406 comprises a central insulated conductor 408 and six outer insulated conductors 410 (only one indicated). The interstitial space within the tape and/or jacket 406, not occupied by the central insulated conductor 408 and six outer insulated conductors 410 may be filled with a suitable filler material, which may be made of either an electrically conductive or an electrically non-conductive material. The central insulated conductor 408 and six outer insulated conductors 410, each have a plurality of conductors 412 (only one indicated), and insulating material 414 surrounding the conductors 412. Preferably, the conductor 412 is a nickel coated copper conductor. Optionally, a polymeric material may be disposed in the interstitial spaces 416, formed between armor wires, as well as formed between armor wires and tape jacket 406.

FIG. 5 represents, by stylized cross-section, a monocable design using armor wires of the invention. The cable 500 includes two layers of armor wires, 502 and 504, surrounding a tape and/or tape jacket 506. The armor wire layers, 502 and 504, include armor wires, such as armor wire 200 in FIG. 2, comprising a high strength core and a corrosion resistant alloy outer clad. The central conductor 508 and six outer conductors 510 (only one indicated) are surrounded by tape and/ or jacket 506 and layers of armor wires 502 and 504. Preferably, the conductors 508 and 510 are nickel coated copper conductors. The interstitial space formed between the tape and/or jacket 506 and six outer conductors 510, as well as interstitial spaces formed between the six outer conductors 510 and central conductor 508 the may be filled with an insulating material 512 to form an insulated conductor. Optionally, a polymeric material may be disposed in the interstitial spaces 516, formed between armor wires, as well as formed between armor wires and tape jacket 506.

FIG. 6 illustrates one method of preparing cylinders of the invention, which may be used as armor wires, among other equipment. Accordingly, a core A, which may be low density titanium or its alloys, is provided. At point 602, the core A may optionally be coated with a bonding layer B, such as brass using a hot dip or electrolytic deposition process. At point 604 the optional bonding layer coated core A is brought into contact with a sheet of corrosion resistant alloy material C, such as, by nonlimiting example, Inconel® nickel-chromium based alloy. The alloy material C is used to prepare the corrosion resistant alloy outer clad. At points 606, 608, and 610, the alloy material is formed around the optional bonding layer core A, using, for example, rollers. Such forming of the alloy material is done at temperatures ranging between ambient temperature and about 850° C. Additionally, the optional bonding layer B may flow and to sufficiently provide a slipping interface between the high strength core A and the corrosion resistant alloy outer clad comprised of alloy material C.

At point 612, the cylinder may be further drawn down (not necessarily to scale as illustrated) to a final diameter to form an armor wire D for example. The drawn thicknesses of the optional bonding layer coated core A alloy clad C may be proportional to the pre-drawn thickness.

FIG. 7 illustrates another method of preparing cylinders of the invention. According to this method, a core A is provided, and at point 702, the high strength core A is optionally coated with a bonding layer B. At point 704 the optional bonding layer coated core A is brought into contact with two separate sheets of corrosion resistant alloy material, D and E, to form the corrosion resistant alloy outer clad. At points 706 and 708, the sheets of alloy material are formed around the optional bonding layer coated core A. At point 710, the cylinder may be drawn down to a desired diameter to form cylinder F which may be an armor wire, for example.

FIG. 8 illustrates yet another method of preparing cylinders of the invention, in an extrusion and drawing technique. Accordingly, a core A is provided, and at point 802, a corrosion resistant alloy outer clad B is extruded over core A. The material forming the corrosion resistant alloy outer clad B may be hot or cold extruded onto the core A. At 804, the cylinder may be drawn down (not necessarily to scale as illustrated) to a final diameter to form C. Further, the core A may be optionally coated with a bonding layer prior to extruding the corrosion resistant alloy outer clad B.

Referring now to FIG. 9, a cross-sectional generic representation of some cables using armor wires of the invention that include a polymeric material disposed about the armor wires. The cables include an insulated conductor core 902 which comprises insulated conductors in such configurations as heptacables, monocables, coaxial cables, slickline cables, or even quadcables. A polymeric material 908 is contiguously disposed in the interstitial spaces formed between layers of armor wires 904 and 906, and interstitial spaces formed between the armor wires 904 and core 902. The layers of armor wires 904 and 906 are composed of armor wires comprising a low density core and a corrosion resistant alloy outer clad. The polymeric material 908 may further include short fibers. The inner armor wires 904 are evenly spaced when cabled around the core 902. The polymeric material 908 may extend beyond the periphery of outer armor wire layer 906 to form a polymeric jacket thus forming a polymeric encased cable 900.

The materials forming the insulating layers and the polymeric materials used in the cables may further include a fluoropolymer additive, or fluoropolymer additives, in the material admixture used to form the cable. Such additive(s) may be useful to produce long cable lengths of high quality at high manufacturing speeds. Suitable fluoropolymer additives include, but are not necessarily limited to, polytetrafluoroethylene, perfluoroalkoxy polymer, ethylene tetrafluoroethylene copolymer, fluorinated ethylene propylene, perfluorinated poly(ethylene-propylene), and any mixture thereof. The fluoropolymers may also be copolymers of tetrafluoroethylene and ethylene and optionally a third co-monomer, copolymers of tetrafluoroethylene and vinylidene fluoride and optionally a third co-monomer, copolymers of chlorotrifluoroethylene and ethylene and optionally a third co-monomer, copolymers of hexafluoropropylene and ethylene and optionally third co-monomer, and copolymers of hexafluoropropylene and vinylidene fluoride and optionally a third co-monomer. The fluoropolymer additive should have a melting peak temperature below the extrusion processing temperature, and preferably in the range from about 200° C. to about 350° C. To prepare the admixture, the fluoropolymer additive is mixed with the insulating jacket or polymeric material. The fluoropolymer additive may be incorporated into the admixture in the amount of about 5% or less by weight based upon total weight of admixture, preferably about 1% by weight based or less based upon total weight of admixture, more preferably about 0.75% or less based upon total weight of admixture.

Armor wires of the invention may also serve as electrical current return or supply wires that provide paths to ground for downhole equipment or tools. The invention enables the use of armor wires for current return while minimizing electric shock hazard. In some embodiments, a polymeric material isolates at least one armor wire in the first layer of armor wires thus enabling their use as electric current return wires. Optical fibers may be used in cables in to transmit optical data signals to and from the device or devices attached thereto, which may result in higher transmission speeds, lower data loss, and higher bandwidth.

FIGS. 10A and 10B illustrate some corrosion resistant cylinder embodiments of the invention. Referring to FIG. 10A, an isometric three dimensional rendering, cylinder 1002 is composed of a core 1004 and corrosion resistant outer clad 1006. FIG. 10B is a cross-sectional illustration of the same cylinder 1002 to further illustrate the embodiment. Cylinder 1002, as well as any cylinder according to the invention, may be sized, drawn, machined, and/or worked by any means known to those with skill in the art, to form wires and tools useful for wellbore applications.

Referring now to FIG. 11A, an isometric three dimensional rendering of other cylinders, cylinder 1102 is defined by core 1104 and corrosion resistant outer clad 1106. In addition, cylinder 1102 is a hollowed body, such as a tube, the outer surface having corrosion resistant outer clad 1006 and the inner surface, corrosion resistant inner surface clad 1108 core 1104. FIG. 11B is a cross-sectional illustration of cylinder 1102 for further illustration. Now referring to FIG. 12, an isometric three dimensional rendering of a cylinder that is a tubular with an O-ring groove, tubular 1202 has core 1204 and outer clad 1206 on the outer periphery of the core 1204. Tubular 1202 also has inner surface clad 1208 lining the hollowed inner portion of tubular 1202. As an additional feature, tubular 1202 has groove 1210 on the outer surface to accommodate a sealing ring, such as an O-ring. In some instances, tubular 1202 may be formed over a mandrel and drawn to form flow tube or other WHE, in such way as maintaining the relative thicknesses of original layers are maintained.

The particular embodiments disclosed above are illustrative only, as the invention may be modified and practiced in different but equivalent manners apparent to those skilled in the art having the benefit of the teachings herein. Furthermore, no limitations are intended to the details of construction or design herein shown, other than as described in the claims below. It is therefore evident that the particular embodiments disclosed above may be altered or modified and all such variations are considered within the scope and spirit of the invention. In particular, every range of values (of the form, “from about a to about b,” or, equivalently, “from approximately a to b,” or, equivalently, “from approximately a-b”) disclosed herein is to be understood as referring to the power set (the set of all subsets) of the respective range of values. Accordingly, the protection sought herein is as set forth in the claims below. 

1. A bimetallic corrosion resistant cylinder comprising a corrosion resistant alloy outer clad and a core, wherein the cylinder is used in wellbore equipment.
 2. The cylinder according to claim 1 wherein the core is a low density core.
 3. The cylinder according to claim 2 wherein the low density core is substantially titanium or titanium alloy.
 4. The cylinder according to claim 1 wherein a bonding layer is placed between the core and the corrosion resistant alloy outer clad.
 5. The cylinder according to claim 1 wherein the cylinder is a solid body.
 6. The cylinder according to claim 1 wherein the cylinder is a hollow body.
 7. The cylinder according to claim 6 wherein the inner surface of the hollow body has a corrosion resistant alloy inner clad disposed thereon.
 8. The cylinder according to claim 1 as used to form a WHE-pressure control device, a chain, a marine termination, a tool housing, a tractor housing, a riser, a casing tube, a pipe, a coil tubing, a spring, a fastener, a coupler, a centralizer, surface production facilities, wellhead equipment, dowhhole completion hardware, control lines, or BHA assemblies.
 9. The cylinder according to claim 2 wherein the low density core is titanium or a titanium alloy, and the corrosion resistant alloy outer clad is an alloy comprising nickel in an amount from about 10% to about 60% by weight of total alloy weight, chromium in an amount from about 15% to about 30% by weight of total alloy weight, molybdenum in an amount from about 2%f to about 20% by weight of total alloy weight, and cobalt in an amount up to about 50% by weight of total alloy weight.
 10. The cylinder according to claim 1 comprising no greater than one corrosion resistant alloy outer clad, wherein the corrosion resistant alloy outer clad comprises an alloy selected from the group consisting of beryllium-copper based alloys, copper-nickel-tin based alloys, superaustenitic stainless steel alloys, nickel-cobalt based alloys, nickel-chromium based alloys, nickel-molybdenum-chromium based alloys, and any mixtures thereof.
 11. The cylinder according to claim 1 comprising no greater than one corrosion resistant alloy outer clad, wherein the corrosion resistant alloy outer clad comprises a nickel-chromium based alloy or a nickel-cobalt based alloy.
 12. The cylinder according to claim 1 comprising no greater than one corrosion resistant alloy outer clad, wherein the corrosion resistant alloy outer clad is extruded over the low density core, and the clad and core are drawn to a desired diameter.
 13. The cylinder according to claim 1 comprising no greater than one corrosion resistant alloy outer clad, wherein the corrosion resistant alloy outer clad is at least one sheath of corrosion resistant alloy, and the clad is formed over the low density core, and wherein the clad and core are drawn to a desired diameter.
 14. The cylinder according to claim 2 wherein the low density core has a density up to about 4.8 g/cm³.
 15. An electric cable according to claim 14 wherein the low density core has a density from about 4.2 g/cm³ to about 4.8 g/cm³.
 16. The cylinder according to claim 2 wherein the cylinder is used to form armor wires for electrical cables.
 17. The cylinder according to claim 1 in which the cylinder is abrasion and corrosion resistant, galling and corrosion resistant, or abrasion, galling and corrosion resistant,
 18. A method of forming bimetallic corrosion resistant cylinder comprising: a. providing a core, b. bringing the core into contact with at least one sheath of corrosion resistant alloy material, c. forming the sheet of corrosion resistant alloy material around the core, and drawing the combination of the alloy material and core to a final diameter to form the cylinder.
 19. The method according to claim 18 wherein the core is a low density core.
 20. The cylinder according to claim 19 wherein the low density core is substantially titanium or titanium alloy.
 21. The method according to claim 18 wherein a bonding layer is placed between the core and the corrosion resistant material.
 22. The method according to claim 18 wherein the cylinder is a solid body.
 23. The method according to claim 18 wherein the cylinder is a hollow body.
 24. A method according to claim 18 further comprising coating the low density core with a bonding layer before forming the sheath of corrosion resistant alloy material around the low density core.
 25. The method according to claim 18 wherein the corrosion resistant alloy material is extruded over the core, and the clad and core are drawn to a desired diameter. 